Matrix Properties Answers

1. a. e.g.  and its additive inverse .
b. The identity element for addition is .
c. e.g.  and its inverse .
d. The identity matrix for multiplication is .

If A = , B = , C = , D = 

2.
a.
b.
c.
 That 2 X 2 matrix multiplication is NOT commutative.
3.
a.
b.
c,
 That 2 X 2 matrix multiplication is associative.
4.
a.
 2
b.
 -17
c.
 -3
5.
a.
b.
c.

6.

a.
b.
c.

7. a. = 

b. is the identity 2 X 2 matrix for multiplication.

c. .

8. (i) Determinant of R = 1
(ii) Inverse of R = 
(iii) 

9.(i) Determinant of A = 1
(ii) The inverse of A = 
(iii) AB = 

10.  = 
This matrix is the identity 2 X 2 matrix for multiplication.